To enable a gas turbine to be inspected and serviced, the gas turbine must first of all be run down from the power mode thereof and cooled down for a sufficiently long time. Inspection and servicing work can begin on completion of an appropriate cooling-down process of the gas turbine, which in some cases can take approximately twenty-four hours. During the cooling-down process, the gas turbine is not available for its intended use.
It is therefore technically desirable to shorten the length of a cooling-down process of a gas turbine and thereby to increase availability of the gas turbine.
One technical approach to a solution for this problem is taught by WO 2006/021520 A1, according to which a liquid is introduced into the compressor during the cooling down of the gas turbine by adding the liquid to the air flow ahead of the compressor.
However, the fact that an excessive addition of liquid can cause damage to the hot components of the gas turbine due to excessive temperature gradients can have a disadvantageous effect according to the prior art. Stress damage of this kind can occur especially with very thick-walled components.